why is light called an electromagnetic wave??what does it have to do with electricity and magnetism?
This should help: http://en.wikipedia.org/wiki/Electromagnetic_radiation
Light is one part of the electromagnetic spectrum. It is called light for convenience and historical reason and to distinguish it from other parts of the spectrum.
So in fact light is an electromagnetic wave.
Or in the other way: An electromagnetic wave with a frequency of some tens or hundreds Terahertz is light. Electromagnetic waves of other frequencies are called differently.
Separate names with a comma.